While the assumption of regimented commitments is an useful idealisation, it can be too strict in many applications. Commitment violators might refuse to compensate, are not capable of compensating/paying fine, or even attempt to escape enforcement. Relaxing this assumption, herein we have comparatively explored institutional punishment of commitment violators and reward of commitment fulfillers as suitable mechanisms to enhance commitment compliance and thus the overall cooperation in the population. We have shown that, given the same, sufficiently high, per capita budget for supplying incentives, reward results in a higher level of commitment compliance and cooperation than punishment.
This is an useful observation for practical applications since reward does not have the above-mentioned enforcement issues, while punishment does. However, it might be more costly for the institutions to provide rewards when compliant behaviour is frequent. An interesting direction is to consider how to combine reward and punishment in a cost efficient way, as have been done in the context of social dilemmas (without considering commitment-based behaviours) [1]}, [2]}, [3]}, [4]}, [5]}.
